+#define IS_MM_ELEMENT(e) ((e) >= EL_MM_START && \
+ (e) <= EL_MM_END)
+
+#define IS_DF_ELEMENT(e) ((e) >= EL_DF_START && \
+ (e) <= EL_DF_END)
+
+#define IS_MM_WALL(e) (((e) >= EL_MM_WALL_START && \
+ (e) <= EL_MM_WALL_END) || \
+ ((e) >= EL_DF_WALL_START && \
+ (e) <= EL_DF_WALL_END))
+
+#define IS_DF_WALL(e) (((e) >= EL_DF_WALL_START && \
+ (e) <= EL_DF_WALL_END))
+